Method of knitting run-proof fabric

ABSTRACT

Run-proof courses are formed by providing alternate needles of a circular knitting machine with loops formed of independent yarns and thereafter pulling one of said yarns from said alternate loop and interlooping the pulled yarn through an adjacent loop.

United States Patent [1 1 Uhlir METHOD OF KNITTING RUN-PROOF FABRIC [75]lnventor: Pavel Uhlir, Trebic, Czechoslovakia [73] Assignee: Elltex,Zavody textilniho strojlrenstvi generalnl, Liberec, Czechoslovakia [22]Filed: Aug. 21, 1970 [21] Appl. No.: 65,978

[30] Foreign Application Priority Data Sept. 3, 1969 Czechoslovakia6013/68 [52] US. Cl 66/14, 66/104, 66/172 R [51] Int. Cl. D041) 9/10,D04b 15/06 [58] Field of Search 66/14, 107, 104,

[5 6] References Cited UNITED STATES PATENTS 2,379,649 7/1945 Nebel66/169 A Aug. 14, 1973 1,309,582 7/1919 Miller 66/172 R 2,313,294 3/1943Garric... 66/172 R 3,046,768 7/1962 Barton 66/172 R FOREIGN PATENTS ORAPPLICATIONS 6,756 9/1956 Germany 66/107 Primary Examiner-Wm. CarterReynolds Att0rney-Richard Low and Murray Schaffer [57] ABSTRACTRun-proof courses are formed by providing alternate needles of acircular knitting machine with loops formed of independent yarns andthereafter pulling one of said yarns from said alternate loopandinterlooping the pulled yarn through an adjacent loop.

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BACKGROUND OF THE INVENTION The present invention relates to theknitting of fabric hosiery and, in particular, to a system for forming arun-proof course or un-rippable course on circular knitting machines.

It has heretofore been required to make substantial constructionalmodification to adapt circular knitting machines to the knitting ofrun-proof fabrics and especially to the knitting of a single run-proofcourse after normal knitting of body fabrics have been made. It has beenespecially difficult to form the final or binding course in such itemsas ladies or mens hosiery of the full fashion variety, or the finishingof courses in such gusset parts as formed the heel and toe portion.

In the copending application Ser. No. 872,182, filed on Oct. 29, 1969,there is disclosed, a method of forming run-proof course on circularknitting machines in which the needles of a circular knitting machineare separated in a 1:1 ratio to form two groups. Onto one group. ofneedles is simultaneously fed a pair of yarns to form double loopsthereon. Thereafter a pair of yarns is simultaneously fed over thesecond group of needles to form an. alternating set of double loops. Asingle course is then formed by pulling one yarn from each. pair ofyarns throughthe loops formed by the alternatively located loops.

While the method disclosed in the aforementioned application producedrun-proof courses in an efficient manner, considerable intricacy andcomplex operation was required to produce the interlooping double yarns.

It is an object of the present invention to provide an improved systemfor producing run-proof courses.

It is another object of the present invention to adapt circular knittingmachines to produce secure and high strength run-proof courses.

It is another object of the present invention to adapt a circularknitting machine in. a simple manner to the production of run-proofcourses for final binding of hosiery. bodies. or for the binding ofgusset portions thereof while the fabric remains upon the circularknitting: machine. I

It is another object of the present invention to pro vide a circularknitting machine with a system for improving. fabric construction.

SUMMARY OF THE INVENTION According to the present invention, there isprovided a system for knitting run-proof courses in a circular knittingmachine having a plurality of needles each having associated with it aknock over sinker and adividing sinker cooperating to form, from yarnfed thereto, a plurality of sequential loop courses constituting thebody portion of the fabric. The system comprises the steps of separatingthe needles, after the completion of the body portion, into two equalgroups ina 1:1 ratio; thereafter feeding to the needles of onegroupayarn, so as to form loops over the edges of the associatedknock-over sinkers and sinker loops over the active edges of thedividing sinkers. Subsequently, feeding to the needles of the secondgroup a second yarn, forming sinker loops over the edges of itsassociated knock-over sinkers and sinker loops over the edges ofthedividing sinker. Thus, sinker loop courses are formed by two separateyarns in alternate needles respectively. Thereafter pulling each yarnthrough the loops of the other yarn, thereby interlooping the two yarnsto form the run-proof course.

A full description of the system of the present invention together withthe various objects and additional advantages thereof is made in theforegoing disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS The following disclosure makesreference to the attached drawings in which:

FIG. 1 is a front elevational view in developed form of a portion of theupper and lower needle cylinders of a circular knitting machine;

FIG. 2 is a side elevational section along line 2-2 of FIG. 1 showingthe upper and lower needle cylinders in detail;

FIG. 3 is view similar to FIG. 1 showing the progress of knitting;

FIG. 4 is a view similar to FIG. 2 taken along line 44 of FIG. 3;

FIG. 5 is a view similar to FIGS. 1 and 3 showing further progress ofknitting;

FIG. 6 is a view similar to FIGS. 1, 3 and 5 showing still furtherprogress of the knitting operation;

FIG. 7 is a view similar to FIGS. 2 and 4 taken along line 7-7 of FIG.6;

FIG. 8 is a view similar to FIGS. 2, 4 and 7 taken along line 8-8 ofFIG. 6; and

FIG. 9 is an enlarged detailed view of the pattem of the fabric showingthe formation of the run-proof course on a body fabric.

FIG. 10 is a schematic view of the sinkers, cam path and sinker curveseffecting the operation of the present invention.

The present invention is shown in connection with a conventionalcircular knitting machine, particularly of the two cylinder variety withmulti-feed' means for the yarn. In the drawings, only those portions ofa circular knitting machine are shown which are necessary for a fullunderstanding of the present invention. It will be obvious that thoseportions not shown are of conventional design and are used in theirconventional and well known manner. Additionally, it will be obvious tothose skilled in the art that the present invention may be adapted toother circular knitting machines of the singular type orof the singlecylinder construction.

Briefly, the circular knitting machine comprises a pair of opposedcylinders l and 12, the lower needle cylinder 1 is mounted on a carryingsleeve 20 and is arranged with a plurality of horizontally parallelneedle beds 2, in each of which a knitting needle 3 is mounted.Intermediate sinkers, patterning sinkers and similar elements are notshown in order to maintain the drawings as simple as possible.

Each knitting needle 3 is provided-with a hook 4 and a cooperating latch5 so as to catch and hold the yarn during the looping operation. Theupper part of the lower cylinder 1 is provided with an integrally formedsinker ring 6 from which is spaced a fixed control ring 7 provided witha cam groove. The ring 7 is secured to a circular member 11 forming theinner throat of the cylinder 1. In the space between the rings 6 and 7,there is provided a plurality of knock-over sinkers 8 each having a butt9 located in the cam groove. There is one knock-over sinker 8 for eachneedle 3. Each knockover sinker 8 has a hook I0 which cooperates withthe respective needle hooks 4 to form a yarn loop.

Mounted above and coaxially with the needle cylinder 1 is the upperneedle cylinder 12. The needle cylinder 12 is also provided with alongitudinally parallel needle bed 13 and with a grooved ring 14 fromwhich is spaced a fixed control ring 18 having a cam groove formedtherein. In the space between the grooved ring 14 and the control ring18 are arranged a plurality of dividing sinkers 15, one each for eachneedle. Each dividing sinker 15 has an edge 16 which is adapted toengage the yarn in similar fashion as the sinker hook l and is alsoprovided with a butt 17 which rides in a cam groove formed in a controlring 18 which is fixed to a circular member 19 forming the inner mouthof the cylinder l2. Yarn guides and feeds are not shown but are includedin the obvious manner.

Turning to FIG. 9, it will be seen that the knitted fabric, according tothe present invention, is formed from a base yarn 21 from which thecomplete body of a hose, for example, in plain or in simple knit, ismade and a run-proof course comprising a set of paired yarns 22 and 24knitted into the hose in a 1:1 ratio. The first yarn is initiallyknitted to half of the terminal loops of the base yarn in what willhereafter be called a first knitting system to form loops 23. The secondyarn 24 is thereafter knitted on to the remaining base loops in whatwill hereafter be called a second knitting system to form loops 25. Thethus formed alternating loops 23 and 25 of each of the knitting systemsare then knitted together in a third knitting system to form a finalrunproof course of needle loops 26 and 27 on either side of themselveson the other alternate needles. Each may have dissimilarcharacteristicsor they may be the same. Elastic or crimped yarn may be used.

For the purpose of fully explaining the procedure by which the presentinvention produces the fabric of FIG. 9, reference is made to FIGS. 1,3, 5, and 6, in particular, which show progressive stages of theprocedure. Each figure is a developed form of the front elevation of theupper and lower needle cylinders l and 12 in the proximity of theknocking-over plane. FIG. 1 shows the initial stages of the firstknitting system, FIG. 3 shows the advanced stages of the first knittingsystem, FIG. shows the stage of the second knitting system while FIG. 6shows the third knitting system and the interknit of the run-proofloops.

The needles 3 are grouped into two sets, one labled a, the second setlabled b. The groups are determined in a lzl ratio by which the needlesare alternately separated. Each needle of each group is given an ordinalsub-number l, 2, and 3 designating the operative position of the needleat any given moment. The numeral 1 designating the lay-up or restposition of the needle, the numeral 2 designating the drawing in orknock-over position respectively of the needle and numeral 3 designatingthe kinking position of the needle. The arrow S as seen in the drawingsdesignates the direction of movement of the cylinders l and I2 and thedirection by which knitting or looping takes place.

Specifically, the apparatus is operated so that the main body of thefabric is formed from the yarn 21 by rotational knitting in theconventional manner. Upon finishing the last of the predeterminedcourses of the body from the yarn 21, all of the needles 3 are drawndown into the lower needle cylinder 1 and thereafter are divided intotheir 1:1 ratio forming the groups of needles 3a, 3a: 3a; and the secondgroup of needles 3b, 3b: 3b;,.

The needles of the first group are then lifted into a lay-up position(3a,). The yarn 22 is then fed independently to the hooks 4 of theneedles (30 while rotation of the cylinders l and 12 is continued. Theneedles (30 then move into the kinking position designated 3a at whichmoment partially completed loops are formed on the hooks 4 of each ofthe needles (3:1 comprising the first run-proof knitting system. Theyarn 22 forms sinker loops 23 over the edge 16 of adjacent dividingsinkers 15. This situation is seen best in FIG. 1. Meanwhile, theneedles of the second group (3b remain in their kinking position sincethey were initially positioned so in the lower cylinder 1.

After all of the needles pass through this first knitting system, all ofthe needles are then for a short time in the kinking position shown inthe left hand side of FIG. 3 and designated (311 or (3b Before thesecond system begins to take effect, the needles of the first group aremaintained in their kinking positions (30 as seen in the right hand sideof FIG. 3. This, of course, is the converse of the positions takenduring operation of the first system. As seen in FIG. 4 those sinkers 15holding loops 22 in the active edge 16 are withdrawn slightly from theposition of FIG. 2 allowing the ascending needles 4 to rise in front ofthe loop 22. Now the second systems yarn 24 is fed independently to thehooks 4 of the needles of this second group B and knitting proceedingonce again from the initial position (3b,) to the take up position (3bBecause of the peculiar shape of the active edges 16 of the sinkers, theyarn 22 is held on the sinkers. While on descent of the needles 4 withthe yarn 24, the yarn 24 is engaged to form its own loops. In thiscondition the active edge 16 of the sinker extends beyond the pointwhere yarn 22 is held so that the yarn 24 is securely held. Thereafterthe sinkers move forward to position seen in FIG. 7. Thus, the secondsystem also produces in the hooks of the needles of this group partialloops comprising loops 25 made over the edges '16 of adjacent dividingsinkers 15.

At the moment when all of the needles of the second system are inkinking position (3b then each hook 4 of all of the needles 3 contain aloop 23 or 25 in such a manner that the loops of the first yarn 22alternate with the loops of the second yarn 24 in alternate needlesrespectively as seen in FIG. 5.

The needles then enter the third phase or system. Prior to this,however, all of the needles are again lifted from the kinking position(3a;,) and (3b;,) to the lay-up position (311 and (3b,) to provide thebasis for finishing the final course. This situation is shown in FIG. 7where the needles sinkers are shown having a loop formed of the secondyarn 24 while the first yarn 22 caught in the working ends 16 of thedividing sinker. The base yarn 21 and the loop 25 are held by knockoversinker 8. As seen in FIG. 5, the needles 3b having made a loop of theyarn 24 are found below the yarn 22 as the needle begins to ascend intothe third system as seen in FIG. 6. Simultaneously, as seen in FIG. 7the sinkers 15 move forward carrying the loop of yarn 24 in front of theneedle, even though these loops also carry the yarn 22. A similar butopposite arrangement can be visualized for the alternate arrangement ofyarns 22 and 24.

In the operation of the third system, the advancing rotation of thecylinders in the direction of arrow S seen in FIG. 6 carries all of theneedles downwardly into the kinking position (30 and 3b As the needlesdescend, the hooks 4 take up the yarns forming the loops over the sinkeredges 16 of the dividing sinkers 15. Thus, the needles of the firstgroup a (first system) serially catch within their hooks 4 the secondyarn 24 so that as a consequence the second yarn 24 is pulled throughthe loops 23 made of the yarn 22 are the first system. In a similarmanner as seen in FIG. 8, the needles of the second group b (secondsystem) serially catch the first yarn 22 of the first system set andpull the yarn 22 through the loops 25 formed from the second yarn 24 ofthe second system. Thus, the run-proof course is finally finished withalternating needle loops 26 and 27 form from the first and second yarns22 and 24 respectively.

The action of said sinkers in forming the said ladder-proof stitchcourse, is obvious from FIG. 10. The graphic representation is based onspecified parts heretofore described. The knitting systems, referred to,are denoted respectively as the first I, second II and third Illknitting system. The course of the controlling butts 17 of the dividingsinkers 15, is represented both in the guiding path formed by fixedcontrolling rings 18 and graphically by a curve whose extreme positionsare denoted by the letters 2,, Z Z 2,. Below this curve a specificadjustment of the sinkers to these extreme positions is shown. Theirdirection of movement, denoted by arrows, in the needle cylinder 1 andthe yarn of which the desired ladderproof course is formed are alsoshown. Finally, the specified knitting systems are in the figure dividedby thin vertical straight lines interlined by two points.

The curve crossing the graphically expressed path 2 of the dividingsinkers 15 is at its verteces denoted by the symbols P, and P and showsthe sinking, tuck and lapping positions of the needles being just placedin action in cooperation with the dividing sinkers. The position denotedas P, means the clearing position and the one denoted as P means thesinking position. This marking by the index 1 and 3 is coincident againwith that appearing in the previous description. I!

It is preferred, of course, that the operation of the knitting machinebe performed in a continuous manner and that the yarn be fed to it in asequential order, to form symmetrical interlocking loops.

At this stage, the individual loops may be removed from the needles in aconventional and well known manner, as by binding off if, it is thefinal run of the hose or by connection with another gusset portion if itis the gusset end.

It will be appreciated that in order to perform the procedure, thedividing sinkers 15 must have a special shape. Accordingly, they areprovided at their ends with a recess for holding a yarn and an activeedge 16 for receiving another yarn and while they are mounted in ananalogous manner to the knock-over sinkers 8, their movement must besuch that at the moment when the hook 4 takes a planar position belowthe knockover plane or the substantially horizontal plane of sinkers115, as shown in FIG. 7, each end 16 terminates its grip on the sinkerloop. An example of this is shown in FIG. 8. The point at which thedividing sinker must be withdrawn being marked by the numeral 15x inFIG. 6.

From the foregoing, it will be seen that a simple and improved systemfor utilizing a circular knitting machine for the formation of run-proofhas been effected. It will also be seen that the run-proof course is infact strong, stable and highly effective, having alternating loops ofdifferent yarn which are themselves interlooped.

It will also be obvious to those skilled in the present art that thesystem may be adapted to a single system knitting machine or to a singlecylinder knitting machine or even to a multiple system, the essencebeing in the formation of the loops which can be effected in a varietyof ways. It will be appreciated that the needles may be divided intothree or even four groups and that multiple yarns maybe used. It istherefore intended that the present disclosure be illustrative only andnot limiting of the scope of the invention.

What is claimed:

ll. The method of knitting a run-proof course on a double cylindercircular knitting machine having a plurality of needles each having anassociated knock-over sinker in the lower cylinder and a dividing sinkerin the upper cylinder, comprising the steps of knitting on said needlesand sinkers a series of knit stitch courses from a base yarn fedthereto, thereafter separating said needles in the lower cylinder in a1:1 ratio to form two groups therefrom, holding one group of saidneedles inactive and moving the dividing sinkers forward and feeding tothe other of said groups of needles a first independent yam so as toform knit stitches with said first yarn while supporting said yarn onall the dividing sinkers thereof to form a first set of loops,withdrawing the dividing sinkers associated with said needles to permitthe needles of said other group to pass in front of the loops heldthereon, thereafter holding said other group of needles inactive on saidlower cylinder and feeding to said one group of needles a secondindependent yarn so to form knit stitches with said second yarn whilesupporting said second yarn on all the dividing sinkers thereof to forma second set of loops, said independent yarns forming a single course ofknit stitches of said first and second yarns with the knit stitches ofthe last course of said base yarn, thereafter moving all of saiddividing sinkers forward to permit the needles of both groups to pass tothe rear of said first and second sets of loops on said dividingsinkers, raising said needles, withdrawing said dividing sinkers asneedles of both groups are lowered to feed said first and second sets ofloops on said dividing sinkers to said needles, continuing to lower saidneedles to pull each of said independent with said needles through theknit stitches of said first and second yarns to form a complete knitstitch course and thereafter finishing off said pulled loops.

1. The method of knitting a run-proof course on a double cylindercircular knitting machine having a plurality of needles each having anassociated knock-over sinker in the lower cylinder and a dividing sinkerin the upper cylinder, comprising the steps of knitting on said needlesand sinkers a series of knit stitch courses from a base yarn fedthereto, thereafter separating said needles in the lower cylinder in a1:1 ratio to form two groups therefrom, holding one group of saidneedles inactive and moving the dividing sinkers forward and feeding tothe other of said groups of needles a first independent yarn so as toform knit stitches with said first yarn while supporting said yarn onall the dividing sinkers thereof to form a first set of loops,withdrawing the dividing sinkers associated with said needles to permitthe needles of said other group to pass in front of the loops heldthereon, thereafter holding said other group of needles inactive on saidlower cylinder and feeding to said one group of needles a secondindependent yarn so to form knit stitches with said second yarn whilesupporting said second yarn on all the dividing sinkers thereof to forma second set of loops, said independent yarns forming a single course ofknit stitches of said first and second yarns with the knit stitches ofthe last course of said base yarn, thereafter moving all of saiddividing sinkers forward to permit the needles of both groups to pass tothe rear of said first and second sets of loops on said dividingsinkers, raising said needles, withdrawing said dividing sinkers asneedles of both groups are lowered to feed said first and second sets ofloops on said dividing sinkers to said needles, continuing to lower saidneedles to pull each of said independent with said needles through theknit stitches of said first and second yarns to form a complete knitstitch course and thereafter finishing off said pulled loops.